1. Field of the Invention
The invention relates to a shoe or boot for use in sports, and particularly in skiing, of the type having a double upper, and to a method used to manufacture such a shoe. More particularly, the invention provides improved boots adapted essentially for cross-country skiing, touring, mountaineering skiing, and off-trail skiing.
2. Description of Prior Art
Boots used in cross-country skiing and the like differ from competition cross-country ski boots in that they are provided with extended uppers which serve to better protect the skier against entry of cold air and snow. The various models of downhill ski boots having extended uppers on the market comprise extended uppers which are made either of leather, or out of molded rubber and are laced on top of the foot. The extended uppers further comprise applied reinforcement elements which are pieces of leather sewn to the exterior of the uppers. Furthermore, boots having extending uppers are provided, in the middle of the malleoli, or ankle bones, with padding sections which are stitched to the corresponding edge of the upper such that they form a sealing bead. Generally, such boots are lined with a foam layer or fur, which may or may not be synthetic, so as to ensure the comfort of the foot in the boot.
Where the boot uppers are made out of molded rubber, the boots are extremely heavy and uncomfortable by virtue of the formation of hard folds or wrinkles during flexion in the metatarsal zone, for example. Furthermore, such boots provide very little thermal insulation as a result of the very nature of the rubber, despite the intenal fur lining. Finally, as in many cross-country ski boots having extended uppers or shafts made of leather or a synthetic material, such boots are provided with stitching of the reinforcement, padding, and/or decoration sections which are transverse stitches. The permeability of such stitching during passage through deep and/or wet snow adds to the inconvenience of their relatively high weight.
Other solutions to moisture and temperature penetration problems have been provided in certain double-upper mountain boots. Unfortunately, these solutions cannot be adapted to cross-country ski boots which manufacturers are presently prepared to manufacture, and which combine strength, comfort and lightness. In effect, the technique of forming such mountain boots having a double upper requires the use of high-quality materials, such as leather, which have material thicknesses which limit the possibility of shaping them, and which themselves add to the weight of the boot. Furthermore, known techniques of assembling such boots include a series of manual operational steps which are relatively substantial both with respect to the overall amount of time which they require as well as the substantial number of individual manufacturing operations, which further increases the costs of manufacture and handling.